[PATCH 13/15] x86/cpu: Make CONFIG_X86_CX8 unconditional

Ingo Molnar
2025-12-14T08:48:11Z

I.e. it's a boot time requirement for the CPU to support it.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ahmed S . Darwish <darwi@linutronix.de>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: H . Peter Anvin <hpa@zytor.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250425084216.3913608-14-mingo@kernel.org
---
arch/x86/Kconfig | 2 +-
arch/x86/Kconfig.cpu | 3 +--
arch/x86/Kconfig.cpufeatures | 1 -
3 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 2e31ca35de1a..7a28380a8d76 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -134,7 +134,7 @@ config X86
select ARCH_SUPPORTS_AUTOFDO_CLANG
select ARCH_SUPPORTS_PROPELLER_CLANG if X86_64
select ARCH_USE_BUILTIN_BSWAP
- select ARCH_USE_CMPXCHG_LOCKREF if X86_CX8
+ select ARCH_USE_CMPXCHG_LOCKREF
select ARCH_USE_MEMTEST
select ARCH_USE_QUEUED_RWLOCKS
select ARCH_USE_QUEUED_SPINLOCKS
diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index c855db6ff6a4..54545aa95286 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -269,7 +269,6 @@ config X86_HAVE_PAE

config X86_CX8
def_bool y
- depends on X86_HAVE_PAE || M586TSC || M586MMX || MK6 || MK7 || MGEODEGX1 || MGEODE_LX

# this should be set for all -march=.. options where the compiler
# generates cmov.
@@ -281,7 +280,7 @@ config X86_MINIMUM_CPU_FAMILY
int
default "64" if X86_64
default "6" if X86_32 && (MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MVIAC3_2 || MVIAC7 || MEFFICEON || MATOM || MK7)
- default "5" if X86_32 && X86_CX8
+ default "5" if X86_32

config X86_DEBUGCTLMSR
def_bool y
diff --git a/arch/x86/Kconfig.cpufeatures b/arch/x86/Kconfig.cpufeatures
index 888487e109bf..1857f75a19d6 100644
--- a/arch/x86/Kconfig.cpufeatures
+++ b/arch/x86/Kconfig.cpufeatures
@@ -42,7 +42,6 @@ config X86_REQUIRED_FEATURE_NOPL

config X86_REQUIRED_FEATURE_CX8
def_bool y
- depends on X86_CX8

# this should be set for all -march=.. options where the compiler
# generates cmov.
--
2.51.0